I got in last night and was able to play with my buddy. The tutorial in this game is just downright dumb. You can't invite players into your session (even though you start in a server) you can't join your friends session in progress, or really do anything until you do the first hand full of missions, ending with a team death match.
But after we got it all figured out it was a blast. We started off buying masks, and hit a few shops in Los Santos, got chased out, went into Blaine County and hit up a few stores there. A player showed up in a helicopter, and picked us up after I crashed my car in a river (luckily I had insurance). We then started to rob more stores via helicopter. My buddy accidentally killed me TWICE while robbing, both times hit the trigger to kill the clerk, but he was standing too close to me and hit me with his shotgun.
It was funny, but you lose a lot of money when that happens.
We then did a few death matches, which were surprisingly more fun than I ever thought they could be. That was probably due to an overwhelmingly positive group of people.
My first few minutes waiting for my friend to log on were hell though. I was in a server of just assholes. I was buying some guns and as soon as i get out, a player kills me, steals my car, says "thanks for the car, asshole" and then proceeds to wreck it. Of course this didn't destroy the car and the insurance company wouldn't answer my call. I had to get my car out of the impound, which gets you two stars, and get free. As it turns out, my car was almost undriveable, and another player was killing me as I was trying to do just save my car. I love that car (Sabre GT Red with white stripes), and I managed to get it in driving condition again, which was good.
Overall, best GTA experience I've ever had, and this includes GTA IV online, which I always enjoyed free play on. The free roam is a little barebones when compared to RDR (I loved raiding bandits in that game), but its still phenomenal.